Liner panels

ABSTRACT

A building panel ( 1 ) is made from a laminate of polystyrene (EPS) (A) as a core material to provide rigidity and flexible sheet materials (B) preferably including kraft paper. Multiple layers of the core material (A) and kraft paper (B) can be used to provide a panel which is lightweight, waterproof, has good impact resistance and insulation properties and is easily worked with conventional tools. The panels are formed using a sheet laminating process and fire retardant adhesives improve the fire rating.

TECHNICAL FIELD

The present invention relates to liner panels and in particular panels of the type used for lining internal walls or ceilings in dwellings, and in addition panels used for suspended ceilings.

BACKGROUND ART

Materials used for the construction of liner panels have not changed greatly over the years.

Internal walls in dwellings are invariably lined with plasterboards such as GIB ROC™.

Plasterboards are relatively inexpensive, easily repaired and worked, papered, plastered and painted.

Plasterboards however do have the inherent disadvantage of being easily damaged by moisture, and of being relatively heavy and are not suitable for suspended ceiling applications.

Materials used for forming panels for suspended ceilings where weight is a consideration include gypsum, cork, fibreboards and the like.

Whilst these materials are satisfactory they tend to break easily and often become unsightly even after a short period of use.

Attempts have been made to provide alternatives to the more commonly used materials described above, including the use of lightweight foam materials.

U.S. Pat. No. 4,121,958 discloses wall board structures based on a rigid closed cell polyurethane core.

The patent also describes in some detail the problems associated with laminating with this material.

In recent times expanded polystyrene foam (EPS) have been used for their insulation qualities in sandwich panels for cool rooms and the like.

EPS materials have the advantage of being lightweight, have relatively good insulation qualities, are water resistant, and are relatively tough.

The low thermal conductivity of EPS is made up from the conductivity of air within the cellular structure, the conduction of the solid polystyrene, and radiation across the fine cellular structure of each bead that forms the sheet.

The smallest contributor to thermal conductivity of EPS is the polystyrene itself, and this contribution is in the order of 10% of the total only.

Still air is an excellent insulating material.

Because of this, the permanently entrapped air within the cells of EPS ensures its very low thermal conductivity.

It is these factors which give EPS its outstanding thermal insulation properties.

It is an object of the present invention to provide a liner panel for use as a wall or ceiling lining having a core layer or layers of EPS

Further objects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to the present invention, there is provided a liner panel comprising a laminate of flexible sheet including a paper and a semi-rigid foam material characterised in that the flexible material is interposed between two layers of the rigid material.

The rigid material can be EPS.

The wallboard can comprise a first layer of kraft paper, a second layer of polystyrene foam, a third layer of paper and a fourth layer of polystyrene foam.

The panel may include a fifth layer of paper laminated to said fourth layer of polystyrene foam.

The panel can be approximately 20 mm thick.

Sheets of the laminate can be attached using a fire retardant bonding agent or adhesive.

A suitable fire retardant adhesive can be obtained from C.W. Hartley Pty Limted, 116 Kitchener Road. Ascot, Queensland, 4007.

The sheets of polystyrene can be of substantially equal thickness.

The sheets of the paper can be of equal or variable thicknesses.

The laminate can be formed in a single stage process.

The laminate can be formed in a two-stage process.

The laminate can be crushed to improve rigidity, to reduce thickness and to improve impact resistance.

The preferred flexible sheets for use in the present invention include paper or cardboard with paper being especially preferred. The paper may be formed from (i) sulphite, (ii) sulphate or (iii) “soda” processes as is known in the art and may be bleached paper or unbleached paper. It is especially preferred to utillse kraft paper which is derived from the sulphate process referred to above. Preferably the kraft paper which is utilised has a thickness of 33-215 gsm (gram per square metre) although this is not essential.

Outer sheets for use in the laminate of the invention may be of any suitable type and comprise plastics sheets, sheets formed from metal foil such as aluminium foil, or sheets formed from textile fabric.

Timber veneer sheets or sheets sold under the LAMINEX trade mark may also be utilised as cover sheets

BRIEF DESCRIPTION OF DRAWINGS

Aspects of the present invention will now be described with reference to the accompanying drawings in which;

FIG. 1 is a sectional drawing of one possible form of panel according to the present invention, and

FIG. 2 is a plan view of a form of panel according to another aspect of the present invention and, FIG. 2 a is an end view of the sheet material of FIG. 2, and

FIG. 3 is a cross-sectional drawing of a panel according to a further aspect of the present invention, and

FIGS. 4 and 4 a are schematic drawings in side view and plan of a laminating process according to another aspect of the present invention.

With respect to FIGS. 1 and 2 and 2 a of the drawings a panel according to the present invention can be a laminate of sheet materials comprising;

-   -   (i) a core layerA,     -   (ii) outer layers B, or     -   (iii) outer layers comprising materials C & D or B

The core layer A may be a sheet of expanded polystyrene form (EPS).

External layer B may be fibreboard such as kraft paper.

An external layer C & D may be a pre-made laminate of kraft paper and another material such as aluminium foil, plastics sheeting or the like.

In an alternative construction the core layer A may be lined on one side with a material B such as kraft paper and on another side with a material such as plastics or foil film combined with an innermost kraft paper.

FIGS. 2 and 2 a of the drawings illustrate a sheet material wherein opposed edges 1 have been mechanically crushed by rollers or the like to produce an edge of reduced thickness.

The edges can be used in butt joints to facilitate the job of plastering joints, and to avoid bulging and excessive finishing work.

With respect to FIG. 3 of the drawings and in accordance with a further aspect of the present invention, the panel comprises a laminate of core layers A1 of a semi rigid material such as EPS an intermediate layer of kraft paper E with at least one of the external surfaces lined with kraft paper F or a pre-made laminate of an innermost kraft paper and another material such as aluminium foil, plastics sheeting or the like.

The illustration to the right of FIG. 3 shows the sheet material which has been mechanically crushed to reduce the depth of the sheet from a post laminated depth S of approximately 20 mm to a depth S1 of approximately 12 mm. The reduction in thickness is permanent and greatly reduces impact resistance. The sheet material can be crushed to suit various depth requireinents.

With respect to FIGS. 4 and 4 a of the drawings the laminating process of the present invention involves loading sheets 2 onto a feed-on chute 3 the sheets 2 are then moved one at a time onto a moving conveyor 4.

As each sheet 2 progresses to the rollers 5 in a laminating area, the next sheet may be raised and pushed onto the conveyor 4.

A layer of kraft paper from a roll 6 passes through an adhesive bath 7 and is rolled onto the core sheet.

The excess paper on the edges may be rebate rolled and rollformed underneath the core.

At this stage the bottom kraft paper from roll 8 also with adhesive applied is rolled on to the sheet over and edges of the top sheet.

The laminate passes through several pressure rollers 4 a to bond the surfaces together.

The sheets are cut to the desired length by cutting apparatus at 9 and proceed to the take off chute in region 10, which works the opposite direction to the feed on chute 3.

To eliminate down time the feeder and take-off chutes may be multiplied.

Both chutes 3 and 10 both feed sheets across the path of the conveyor 4. This allows one chute to empty or fill while the second is filled or emptied.

The adhesive baths and the kraft liner board reels may be on rails to enable cleaning of the adhesIve baths at the end of runs to refill the linerboard reels by forklift and to thread the new linerboard through the adhesive baths without crawling under and over the laminating machine.

A boardwalk may be provided to enable the reel of linerboard to fit under the laminating bench.

The process described can be used to produce the liner panels of FIGS. 1 to 3. To achieve the liner panel structure of FIG. 3, two panels having a core layer of EPS and outer layers of kraft paper can be separately formed and then joined together. In such a case, the kraft paper side destined to be innermost can be chosen from a lighter grade of paper because two layers of paper are back-to-back in the FIG. 3 structure.

The process described can be fully or partially automated.

With the laminate combinations envisaged there are many advantages to the present invention including;

-   -   (a) the provision of a lightweight robust and moisture resistant         lining material,     -   (b) the provision of edge rebates to facilitate plastering of         butt joints,     -   (c) a number of material combinations can be used to suit         various applications including interior linings, suspended         ceilings etc, all of which will provide superior insulation and         are relatively easy to install,     -   (d) the liners are readily suited to common forms of attachment         to frames and walls such as fasteners such as nails and screws,         glues and the like,     -   (e) the EPS core materials are non-toxic,     -   (f) the use of fire retardant adhesives provides enhanced fire         resistance,     -   (g) the liners will not readily crack or splinter     -   (h) the liners provide excellent insulation which can be         enhanced by the use of reflective foils and the like, and     -   (i) the liners can be readily coated for enhanced durability and         decorative affect.

Aspects of the present invention have been described by way of example only and it will be appreciated that modificatlons and additions thereto may be made without departing from the scope thereof, as defined in the appended claims. 

1. A liner panel comprising a laminate of flexible material including a paper and a semi-rigid foam material cliaracterised in that the flexible material is interposed between two layers of the rigid material.
 2. A panel as claimed in claim 1 wherein the rigid material is polystyrene.
 3. A panel as claimed in claim 1 comprising a first layer of kraft paper, a second layer of polystyrene foam, a third layer of kraft paper and a fourth layer of polystyrene foam.
 4. A panel as claimed in claim 3 including a fifth layer of krafl paper laminated to said fourth layer of polystyrene foam.
 5. A panel as claimed in any one of claims 1 to 4 wherein the laminate is approximately 20 mm thick.
 6. A panel as claimed in any one claims 1 to 5 wherein the sheets of the laminate are attached using a fire retardant bonding agent or adhesive.
 7. A panel as claimed in any one of claims 1 to 6 wherein the sheets of polystyrene are of substantially equal thickness.
 8. A panel as claimed in any one of claims 1 to 7 wherein the sheets of kraft paper are of equal or variable thicknesses.
 9. A method of forming a panel as claimed in any one of claims 1 to 8 wherein the laminate is formed in a single stage process.
 10. A method as claimed in claim 9 wherein the laminate is formed in a two-stage process.
 11. A method as claimed in claim 9 wherein the laminate is crushed to improve rigidity, to reduce thickness and to improve impact resistance.
 12. A panel substantially as herein described with reference to the accompanying drawings.
 13. A method of forming a panel as herein described with reference to the accompanying drawings. 